How Does Google Know What Ads Will Interest My Audience?

Google's AdSense engine, as with everything Google, is
rather sophisticated. Rather than simply serving up random
ads from its advertiser base, Google
works hard to make sure the ads
your visitors see are likely to pique
their interest.

From the day you start offering
ads, the AdSense robot visits on
a regular basis, reading through
your pages with ads. The robot
takes a look at the words you use,
the frequency with which you use
them, even some of your page structure and formatting (for
example, bigger fonts usually signify something important).
Then Google uses all this info to figure out which ads your
readers will warm to.

Even better, Google takes the language of your site and
the location of your visitors into account, serving up language-
specific, location-targeted ads for maximum impact.
So a visitor from France (or a
person browsing the Internet from
a Frenchified computer) may
see AdWords in French (shown
here) or from French companies,
while your U.S. visitors see theirs in
English, Germans in German, and
so forth. (See What Are Google AdWords for an excellent how-to of that service.)

Bottom line: Google may know
more about your audience than you do. Use AdSense to
work that knowledge to your advantage.

The beauty of AdSense, however, is that it's free—absolutely gratis—to join and
run, so you may as well give it a whirl. And the program automatically tailors itself
to your site over time, supplying more relevant ads as it gets to know you better or
as you change your content. It can take a few months before Google hits the sweet
spot with ads that your readers love, but the only thing you have to do is set it up and
watch it go to work. (Bear in mind, however, that participating in AdSense doesn't have any effect on your site's rank in Google search results.)

Warning: Don't try to game AdSense. It probably won't surprise you a whit to learn that people have set
up sites primarily to showcase ads and draw lots of clicks (and make buckets of money). When Google
finds out about these sites (and it often does) it blocks the ads immediately. But dirty play makes the whole
system weaker, and it harms not only Google but the people who pay for clicks, too. Don't be part of that
damage.

Some Quick Tips for New Users

Google prefers pages with lots of text rather than lots of pictures, because it can better assess what kind of ads will be interesting to your visitors.

If you want to see how your ads look before they go live, you can check them on an online test server.
But keep in mind that if the server is connected to the Internet, Google can see your pages, so it can, and
will, index them.

Google's online help pages for AdSense (https://www.google.com/adsense/online-help)
are chock-full of useful information on setting up shop, getting the most out of the
program, maintaining your account, troubleshooting, and so on. Visit every so often,
especially before you write in for help. If you have a question that isn't answered by
the help pages or is specific to your account, drop the AdSense crew a line using the
form at https://google.com/adsense/contact.

For more help, including instructions on blocking robots other than the Googlebot, check the Troubleshooting
Tips section of the "Google AdSense Technical Implementation Guide" at https://www.google.com/adsense/faq-tech.

Editor's note: This article was excerpted from Google: The Missing Manual. For everything you need to know to become a Google guru, be sure to check out the latest edition.

Sarah Milstein
writes, speaks, and teaches frequently on Twitter. She is also co-founder of 20slides.com, a site for lively, work-related workshops. Previously, she was on the senior editorial staff at O'Reilly, where she founded the Tools of Change for Publishing conference (TOC) and led the development of the Missing Manuals, a best-selling series of computer books for non-geeks. She's written for the series, too, co-authoring "Google: The Missing Manual." Before joining O'Reilly, Sarah was a freelance writer and editor, and a regular contributor to The New York Times. She was also a program founder for Just Food, a local-food-and-farms non-profit, and co-founder of Two Tomatoes Records, a label that distributes and promotes the work of children's musician Laurie Berkner.

Rael Dornfest
is Founder and CEO of Portland, Oregon-based Values of n. Rael leads the Values of n charge with passion, unearthly creativity, and a repertoire of puns and jokes  some of which are actually good.
Prior to founding Values of n, he was O'Reilly's Chief Technical Officer, program chair for the O'Reilly Emerging Technology Conference (which he continues to chair), series editor of the bestselling Hacks book series, and instigator of O'Reilly's Rough Cuts early access program. He built Meerkat, the first web-based feed aggregator, was champion and co-author of the RSS 1.0 specification, and has written and contributed to six O'Reilly books.
Rael's programmatic pride and joy is the nimble, open source blogging application Blosxom, the principles of which you'll find in the Values of n philosophy and embodied in Stikkit: Little yellow notes that think.